Restoring From Automigration Media; Vls Accelerated Deduplication - HP StorageWorks 12000 - Virtual Library System EVA Gateway Manual

nodes in the VLS. If the copy window does not need maximum copy performance, you can use even
fewer tape drives per node.
For example, a 4-node VLS9000 device that needs to automigrate 64 TB every night within an eight
hour copy window (that runs after the backups are complete) requires an aggregate copy performance
of 2200 MB/sec. With a 100-120 MB/sec per copy stream, this implies a tape library would need
18-22 LTO3/LTO4 tape drives to achieve this copy performance. Remember these tape drives should
be evenly spread across both back-end Fibre Channel ports of every VLS node. In other words, half
the drives should be connected to the first back-end Fibre Channel port on every node, and the other
half should be presented to the second back-end Fibre Channel port on every node.

Restoring from Automigration Media

When using automigration to create physical backups, if the destination tape is still loaded in the
destination library, its matching virtual cartridge will still be present in the virtual library. In this case,
the user can simply restore from the virtual cartridge using the backup application.
If the destination tape has been ejected from the destination library, the user has the following options:
1. If the automigration virtual cartridge still exists in the firesafe (for example, if the policy-defined
retention period has not expired), use Command View VLS to manually move the cartridge back
into the virtual library. You can then restore from the virtual cartridge using the backup application,
and then move the cartridge back to the firesafe.
2. If the automigration virtual cartridge has been deleted from the firesafe, retrieve the physical
cartridge by one of the following methods:
• Load the physical cartridge into any compatible physical drive or library that is visible to the
backup application and restore from that tape using the backup application.
• Load the physical cartridge into the destination library and use Command View VLS to perform
a Load Media for Restore, which copies the entire destination tape back into a virtual cartridge.
You can then restore from the virtual cartridge using the backup application.
NOTE:
Customers may choose to configure their devices such that there are additional, unmapped slots in
the virtual library. These additional virtual slots can be used for backups so that even if the physical
slots are all full, there are still spare slots available to hold the cartridges needed for restore. Another
option is to have a separate virtual library for restore operations.

VLS Accelerated Deduplication

HP Accelerated deduplication technology is designed for optimal performance and scalability to meet
the needs of enterprise data centers. It offers the following features and benefits:
• Leverages object-level differencing code, which targets matching backup "objects." Rather than
comparing the current backup with every byte of data stored on the device, Accelerated deduplic-
ation can compare backup objects from the current backup to matching objects from the previous
backup, where there is likely to be duplicate data. This allows the deduplication to be performed
faster, consuming fewer resources.
• Is performed as a post-process. This delivers the fastest possible backup performance, because
there is no loss of bandwidth to the normal backup window.
• Allows data to be retained longer because redundant information is removed from previous
backups, freeing disk space.
148 Virtual Library Systems